8inch came in only cars i believe & the dead give away to tell an 8" from a 9" is on the 3rd member the 2 bolts on the very bottom of the 9" u HAVE to use a wrench to remove it. also the eight inch came only in 28 spline

as for removing its fairly simple. put the car on jackstands, remove ur tires & brake drums. disconnect ur driveshaft, (u might have to disconnect ur brake lines at the wheel cylinder), unbolt the 4 bolts u see on the backing plate, these hold the axle/bearning in. then give the axle a good pull, if it doesnt come out try this. put the brake drum on backwards & tighten up the lugnuts just enuff so the drumm w/still slide on the lugs & then w/the drum as far in as u can get it give it a hard yank. it should act like a slide hammer & pop the axle/bearning out. w/the axles removed start to unbolt the 3rd member, here's a hint:leave 1 or 2 nuts on(but loose) on the top of the 3rd memeber, this way it wont just fall out on u. when all the bolts are off take the top 1 or 2 off & carefully pull the 3rd memeber out. u may have to hit it w/a hammer or use a screwdriver or chisel to break it loose. BUT becarefull when it breaks loose because those thing can & will hurt u ask me i know.
when u put it back together i would replace the seals on the axles & if u dont want to or cant get a 3rd member gasket a good ATV sealer will work just fine. put the 3rd member in the housing, then slide ur axles back in, tighten up the axle bolts, add ur rearend grease, install ur driveshaft, hook up ur brake lines & bleed them(<~~IF u had to disconnect them), & adjust ur brakes & u should be good to go. once the car is in the air i used to do this job in less then hour. normally u'll spend more time jacking the car up & getting ready to do the job & the clean up then u'll have in replacing ur parts..joe